Java Concurrency & Multithreading: beginner to intermediate

Explore the basics of concurrency and multithreading by examining how you switch between kitchen tasks to manage subtasks at once. Note how this differs from true parallelism when others help.

Explore the difference between parallelism and concurrency, illustrate with real-world examples, and introduce the foundations of multithreading, including what is a thread and a process.

Explore the central processing unit as the heart of a computer, learning how it executes instructions one by one at 3.6 GHz and relies on specific instruction sets.

Trace the evolution from punched cards to Atlas Supervisor's multitasking, showing how processes, memory protection, and context switching optimize scheduling and CPU utilization.

Multi-core and multi-CPU systems enable true parallelism by letting independent cores execute tasks simultaneously, with memory storing state to prevent conflicts.

Understand what a thread is relative to a process, how threads share a process's memory, how the OS schedules them on multicore CPUs, and why Java multithreading boosts throughput.

Explore Java thread definitions by comparing subclassing, runnable, and anonymous classes, and learn how to create, run, and manage threads and their states.

Explore the six thread lifecycle states: new, runnable, blocked/waiting, waiting, timed waiting, and terminated, through a real-world grocery store analogy, showing thread creation, start, and execution.

Learn how to start threads using thread class and runnable. Create cashier threads and a manager thread, observe thread lifecycle and isAlive checks, and note that threads cannot be restarted.

Learn how executor service submits threads as callables, offers shutdown capabilities, and abstracts thread management, enabling reusable threads through fixed thread pool, cached thread pool, or single thread executor.

Explore why executor service improves real-world Java concurrency by limiting threads to available cores, reusing threads, and reducing costly context switches with a fixed thread pool.

Explore executor service concepts by simulating cashiers and customers using runnable tasks. Learn how to submit tasks, manage shutdowns, and how threads are reused behind the scenes.

Contrast blocking and non-blocking calls and introduce callable for thread tasks that return a result. Learn how futures from an Executorservice enable checking isDone and using get with optional timeout.

Submit sushi and coffee callables to a cached thread pool and compare blocking waits with concurrent execution. See how article work overlaps with task completion for efficiency.

Explore how Java threads are named, identified, and prioritized, and distinguish diamond versus non-diamond threads, including executor service effects and their practical background uses.

Explore joining and interrupting in Java threads: join blocks until a thread finishes (with timeout), interrupt toggles the flag or raises an exception, and executor service cannot be joined.

Explore atomicity and read-write data races with real-world examples, and see how Java code translates to machine instructions, highlighting why most operations are not atomic.

Discover how CPU bit width defines data representation, from four-bit to sixty-four-bit processors, and how registers, memory transfers, and multi-step operations enable handling larger numbers.

Discover how non-atomic reads and writes of a shared int can cause race conditions in multi-threaded Java programs, influenced by CPU size and context switches.

Explore data race in a bank base rate scenario where managers read the rate while a director updates it, yielding mixed reads. Learn how CPU caches and concurrency affect consistency.

Explore how data race issues arise from CPU caches and instruction reordering, and learn that volatile enforces a happens-before relation, making writes to a volatile field visible before subsequent reads.

Explore how timing and thread sequencing create race conditions in shared data, illustrated by a bakery stock scenario. Learn how thread synchronization prevents data races and guarantees correct outcomes.

Examine a race condition where multiple threads subtract croissants and bagels from shared stock, revealing non-atomic subtraction errors and the need for atomic operations.

Explore how mutual exclusion enforces atomic access in multithreaded code by using mutexes, locks, and monitors, illustrated with a restaurant bathroom analogy and Java usage.

Explore how to use synchronized blocks to acquire a shared monitor, prevent race conditions, and create thread-safe, reentrant code with a shared stock example.

Illustrates the blocked state in Java concurrency with a bakery example, showing three threads contending for a shared monitor where one acquires the monitor and others block, highlighting synchronization costs.

Understand synchronized methods, including instance and static methods, and how this and monitors control access. Learn to wrap collections with Collections.synchronizedList and Collections.synchronizedMap for thread-safe access and monitor sharing.

Explore the compare-and-swap atomic instruction, its address, expected value, and update value inputs, and how it enables lock-free updates in multithreading by retrying until success.

Explore how the atomic package enables thread-safe operations with AtomicInteger and types using compare-and-swap to implement atomic add, and apply it to a bakery example with stock and bagel counts.

Learn practical tips for Java concurrency, including thread local variables that hold per-thread values, and use of parallel streams for easy parallel processing and thread dump debugging.

Conclude the Java concurrency and multithreading course on Udemy with congratulations and a call to leave a review. Invite learners to connect on LinkedIn and share feedback about future courses.